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kiwi cowboy
18th December 2007, 22:09
hi guys n gals
iv just put a new head gasket in my 85 fz750 .
the thing is it now has a knock that seems to be coming from the bottem of the motor [i only had the top end off].
the knock is noticeable at idle and on decelleration at low revs ie just before one would pull the clutch in to stop.
doesent seem to knock when on the power that i can notice.
does anyone have an idea?
the only thing i did when turning the the crank getting ready to install the camshafts i did turn the crank about half a turn clockwise insted of counterclockwise buy mistake would this have done anything?[didnt bind or anything when turned so didnt worry bout it].
cheers for any advise

Paul in NZ
19th December 2007, 05:57
Make sure you have synched the carbs and set the idle at the recommended speed (1250 rpm??). Most 4's will 'knock' if the idles not right due to lash in the drive chain.

Hard to diagnose without seeing / hearing the bike though ;-(

Cheers

F5 Dave
20th December 2007, 16:19
Cam chain tensioner perhaps? Not sure how these are on the FZ which is embarrassing as the YZF is largely the same architecture.

kiwi cowboy
23rd December 2007, 22:52
Cam chain tensioner perhaps? Not sure how these are on the FZ which is embarrassing as the YZF is largely the same architecture.

dont think its the cam tensioner i think its more like the primery chain do these have a tensioner? have synced the carbs made a bit better.
anyone have parts for this model bike?

pete376403
25th December 2007, 17:46
No primary chain in these - gear drive from crank to clutch. I'm making some (slow, it's been pretty low priority)) progress with getting the FZR750 engine apart - have got the clutch off so now should have the trans out soon. Once this is done the rest of the motor wil be more or less surplus to requirements. As far as I know it is was runner. If you need parts let me know

What I think you may have done - when you turn the motor backwards the cam chain tensioner plunger can get pushed in, releasing the chain tension. Check that, and the cam timing again.

Mrs Busa Pete
27th December 2007, 07:48
starter chain can rattle at low reves part of being 20 years old